If there was any doubt Darrell was the same competitor he used to be — the man who won the first four Challenge seasons on which he appeared — it’s been nullified: He’s still a beast. But with his toughest Fortress battle ahead, can he hang tough and survive to the Invasion finals?

On tonight’s episode, the Champions were dealt yet another crushing defeat in “Caved In,” a claustrophobic’s nightmare that challenged players to navigate a series of small, booby-trapped rooms before finally setting themselves free. Still, there was only a second to grieve their sudden $85,000 to $25,000 deficit to the Underdogs, as TJ announced only two Champions would compete in the final mission, and Laurel, Camila, Darrell and CT still remained.

As the final four champs prepared for their last man-to-man battles, Darrell knew his third time in the Fortress would be his toughest. Though he’d already sent monsters Bananas and Zach packing, there was something more threatening about CT, he said.

“I will say that CT will probably be the hardest person for me to face for the simple fact that he has a lot of willpower and determination,” he noted. “But I know I’m in great shape. I stay ready. Just hopefully, nobody gets hurt.”

And CT, who hadn’t yet been forced into the Fortress and knew his lone visit would be a tough one, mirrored the sentiment.

“It’s been a long time since I’ve been in an elimination,” he said. “I’m going up against Darrell, one of the best to ever play this game.”

Each ready for a physical battle, the champs were knocked off balance when TJ announced they’d square off in “Knot So Fast,” a test of strategy and endurance. The game, previously played on Battle of the Seasons and Battle of the Exes II, tasked players to each thread their own ropes through one of two jungle gym structures and try to make as many hopelessly tangled knots as possible. Then, players would switch sides and move to undo their opponents’ handiwork as quickly as possible. The first player to successfully unravel his or her respective mess and drag the rope out of his or her structure would win.

On the women’s side, the game completely leveled the playing field, and Laurel, thought to be unbeatable (she was 9-0 entering the game), was forced to accept her first loss. Camila tore through loops and half-hitches like the Girl Scouts’ most decorated badge-holder and sent Laurel packing.

“First loss ever,” Laurel bemoaned. “I got tangled up a little bit, lost my focus and then I kind of just gave up, and I hate saying that.”

Now, the stage is set for the final elimination round on the Champions’ side — either Darrell will win his third Invasion duel, or CT will be the victor in his first and only appearance. So what do you think — can Darrell pull off the Challenge champion sweep, and will CT be his third and final victim? Or does CT have more to give than did Bananas and Zach, and is there trouble in store for Darrell? Share your thoughts, and see who comes out alive when the next Challenge episode airs Tuesday at 9/8c!